Piston ring groove cleaner



Dec. 3, 1963 M. J. KANE PISTON RING GROOVE CLEANER Filed May '18, 1962 INVENTOR. Maw/c5 J. ATq/vE ,qrrokflw United States Patent 3,112,506 PISTON RING GROOVE CLEANER Maurice J. Kane, 6325 Zilth Ave. NE, Seattle, Wash. Filed May 18, 1962, Ser. No. 195,960 3 Claims. (Cl. 15-104.01)

This invention relates to tools designed for the cleaning of ring grooves as formed in the pistons of certain internal combustion engines. More particularly, it relates to a novel, manually operable form of tool having a scraping member especially shaped for the clearing and cleaning of hard carbon deposits from the bottoms of ring grooves of that kind which are of standard design in pistons of Cummins, Mack and certain other automotive Diesel engines; such grooves being characterized by having what is known in the industry as the taper side or keystone formation.

It is the principal object of this invention to provide a practical, effective and easy to use hand tool for cleaning inwardly tapered ring grooves, without damage to their sidewall and bottom surfaces.

Further objects of the invention reside in the details of formation of the various parts of the tool; in their combination and relationship of assembly and in the mode of use of tool as hereinafter described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings wherein:

FIG. 1 is a perspective view of the groove cleaning tool of the present invention.

FIG. 2 is a cross-sectional view of a piston, taken in a plane perpendicular to its axial line, showing the present tool as applied thereto for the cleaning of a ring groove.

FIG. 3 is a cross-sectional of the tool taken on line 3-3 in FIG. 2 showing its application to a piston groove.

FIG. 4 is an enlarged cross-sectional view of a portion of a piston wall, showing the tapered cross-sectional formation of a tapered groove and the carbon scraping element of the present tool as seated in the groove.

FIG. 5 is an enlarged fragmental portion of a piston wall with tapered ring groove with a guiding wheel of the present tool seated in the groove.

Referring more in detail to the drawings:

It will be explained that the particular formation of the type of ring groove to be cleaned by the present tool is as shown in FIG. 5, wherein it is noted that the opposite side surfaces of the groove are equally inwardly converged or sloped to a flat bottom surface providing a continuous groove of uniform width and depth about the piston wall.

The tool of this invention is designated in FIG. 1 in its entirety by reference numeral 10. It comprises a rigid, substantially semi-circular, frame 12 of a predetermined inside radius, based on the diameter range of pistons with which it is to be used. This frame is of metal and is equipped at one end, herein referred to as its outer end,

with a pair of guiding rollers 14 and 15 that are set within openings 14' and 15', formed through that end portion of the frame, in spacing that provides for the engagement of the rollers with a piston at approximately a 50 interval on its cylindrical surface.

At its other end, the frame is formed with an outwardly extending arm portion 16 terminating in a forwardly extending lateral shoulder 17. The arm portion 16 is formed with a flat forward surface 16s in a radial plane of the frame 12, containing a guide groove 18 extending also in a direction radially of the frame and a roller mounting block 19 is mounted for inward and outward sliding movement on said surface 16s; the block having a guiding rib 20 on its inside face adapted to be received in and for guiding movement in the groove 18. Adjustment of the block inwardly or outwardly along the arm 16 is controlled by a screw bolt 22 that is threaded through the lateral shoulder 17 in a direction radially of the frame and which has a rotatable holding connection at its inner end with the block 19 and at its outer end is equipped with a knurled knob 26 for making turning adjustments of the bolt. The adjusting movement of the block is along a line that is diametric of the frame 12 and which passes midway between the guide rollers 14-15.

The block 19, at its inner end mounts a guide roller 28 of the same dimensions of rollers 14 and 15; all rollers being identical in all dimensions and all are mounted in the same plane to turn freely on mounting axles 30 fixed in parallel relationship to mount the rollers in the central plane of the semi-circular frame 12. Each roller, as noted best in FIG. 5, has an integral cylindrical hub portion H of substantial diameter extending equally to opposite sides of a hub encircling wheel flange f. This guiding flange has opposite side surfaces equally inclined and is so dimensioned so as to be received with close guiding contact between the opposite sidewalls of the piston groove.

When the tool is properly applied to a piston cylinder, the two rollers 14-15 will be seated in the selected groove g at one side of the piston p and the roller 28 will then be adjusted by inward movement of block 19, into the same groove at the opposite side of the piston. When an adjustment has been made, the hub portions of the three rollers will bear against and roll on the piston surface at opposite sides of the groove as in FIG. 5 and the flange portions 1 of each wheel will fit within the groove with substantial clearance between the outer surface of the flange f and the bottom of the groove as at 34.

It is to be understood also that the annular flange of each roller is received in that outer portion of the groove that is normally kept clean by the action of the piston ring fitted in the groove and the material to be cleaned from the groove is usually caked in the bottom portion of the groove below the normal position of the piston ring. Cleaning of the groove is effected by a scraping element now to be described.

The groove cleaning element of this tool is designated in FIG. 1 generally by numeral 50 and it is mounted on the inside surface of the frame 12 in position for its travel in the groove in which the three guide rollers are disposed for travel. This element 50 comprises a mounting stem 51 of cylindrical form that is slidably and rotatably fitted in a hole 52 that is drilled through the frame radially thereof at a point near the radial arm 16. At its inner end the stem 51 mounts a wedge shaped or tapered scraping tool 53 adapted to enter and be moved along the piston groove to scrape its side surfaces and base. Formed integrally with the narrower lower end portion of this wedge shaped scraping element 53 is elongated fin 55 adapted to follow in the groove being cleaned merely for the purpose of keeping the scraping surface of the tool in a position transversely of the groove.

Formed on the frame 12 is an outwardly offset shoulder 60 overhanging the drilled hole 52 in which a screw turning shaft 61 is mounted. This shaft has a turning thumb nut 62 at its outer end and at its inner end has a threaded connection with the outer end of the stem 51 thus to provide for adjusting the scraping wedge radially of the frame into or from the piston groove.

With its parts so formed and assembled, the tool is used as follows: First, the piston ring is removed from the ring groove to be cleaned; the piston fixedly secured in place and the tool It) is then applied over and about the piston as in FIG. 2. In its application the two guiding rollers 14 and 15 are seated in the groove at one side of the piston and the single guide roller and scraping wedge are adjusted into the groove on its opposite sides.

It is to be understood that the hub portions of the rollers 14, 15 and 28 limit the extent of entry of the rollers into the groove to that outer portion thereof that is normally kept clean of carbon deposit, by the movement of the piston ring fitted in the groove. The carbon deposit is principally caked on the bottom surface of the groove and on the inner portions of its sidewalls.

The roller 28 is so adjusted as to retain the hubs of all three rollers in close rolling contact with the piston surface and the scraping wedge is adjusted by turning screw 62, to a proper depth in the piston groove to clean its bottom surface and sides, especially in its narrower bottom portion without damage to the side surfaces. Then, by grasping the portion of the tool frame, as defined by arm 16 and screw bolt 22 the tool is caused to be worked around the piston as inwardly adjusted until the bottom of the groove has been cleaned of all caked on carbon or other foreign matter. By reason of the radial adjustability of block 19 and the roller 28, and the adjustability of the groove scraping wedge, the tool can be made to accommodate pistons of various diameters.

It is also to be understood that rollers may be made in sets in different dimensions to clean grooves of different Widths and which may be interchanged with those of the frame. Also scraping elements may be made to fit grooves of different widths.

What I claim as new is:

1. A tool for cleaning the carbon out of the bottom of piston ring grooves of tapered or keystone formation; said tool com-prising a rigid, substantially semi-circular frame member, a fixed guiding roller mounted on one end portion of said frame for reception in the piston ring groove at one side of the piston, an adjustable guiding roller mounted at the other end of the frame for guided travel in the piston ring groove at a point greater than 180 from said fixed roller; each of said rollers having symmetrically sloped opposite side surfaces corresponding to the spacing and inward sloping of the sidewalls of the groove and having hub portions at their opposite sides for rolling travel on the piston surface at opposite sides of the groove to limit the extent of entry of the rollers into the groove, a tapered groove scraping tool adjustably mounted on the frame between said rollers, said scraping tool including an end portion of inwardly tapered configuration toward its free end and the tapered portion of said scraping tool being less in width than the width of the piston ring groove at the groove opening so that the scraping tool, when positioned in the ring groove, does not engage the sidewalls of the groove except adjacent the base of the groove and so that when the tool is moved circumferentially within the groove it scrapes carbon only from the base thereof.

2. A tool according to claim 1 wherein said semi-circular frame is formed at that end which mounts the adjustable roller with an outwardly extending arm formed with a laterally turned shoulder, said arm having a flat surface in a plane radially of the frame axis, and a block mounted on said flat surface for sliding adjustment thereon radially of the frame and mounting said adjustable roller therein, and a block adjusting screw mounted in said shoulder and having a turning connection at its inner end with said block for its adjustment to adjust the roller accordingly.

3. A tool according to claim 1 wherein the scraping tool includes shank mounted in the frame radially thereof for inward and outward adjustment, an adjusting shaft for said shank, and a fin integral with the tapered portion of said scraping tool for guided travel in the groove to retain the scraping tool in scraping position transversely of the groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,012,314 Vinton Dec. 19, 1911 1,575,054 Ibbetson et al Mar. 2, 1926 1,601,139 Morgal Sept. 28, 1926 1,715,289 Hellman May 28, 1929 1,886,696 Klein Nov. 8, 1932 1,984,155 Prochaska Dec. 11, 1934 Ann..- 

1. A TOOL FOR CLEANING THE CARBON OUT OF THE BOTTOM OF PISTON RING GROOVES OF TAPERED OR KEYSTONE FORMATION; SAID TOOL COMPRISING A RIGID, SUBSTANTIALLY SEMI-CIRCULAR FRAME MEMBER, A FIXED GUIDING ROLLER MOUNTED ON ONE END PORTION OF SAID FRAME FOR RECEPTION IN THE PISTON RING GROOVE AT ONE SIDE OF THE PISTON, AN ADJUSTABLE GUIDING ROLLER MOUNTED AT THE OTHER END OF THE FRAME FOR GUIDED TRAVEL IN THE PISTON RING GROOVE AT A POINT GREATER THAN 180* FROM SAID FIXED ROLLER; EACH OF SAID ROLLERS HAVING SYMMETRICALLY SLOPED OPPOSITE SIDE SURFACES CORRESPONDING TO THE SPACING AND INWARD SLOPING OF THE SIDEWALLS OF THE GROOVE AND HAVING HUB PORTIONS AT THEIR OPPOSITE SIDES FOR ROLLING TRAVEL ON THE PISTON SURFACE AT OPPOSITE SIDES OF THE GROOVE TO LIMIT THE EXTENT OF ENTRY OF THE ROLLERS INTO THE GROOVE, A TAPERED GROOVE SCRAPING TOOL ADJUSTABLY MOUNTED ON THE FRAME BETWEEN SAID ROLLERS, SAID SCRAPING TOOL INCLUDING AN END PORTION OF INWARDLY TAPERED CONFIGURATION TOWARD ITS FREE END AND THE TAPERED PORTION OF SAID SCRAPING TOOL BEING LESS IN WIDTH THAN THE WIDTH OF THE PISTON RING GROOVE AT THE GROOVE OPENING SO THAT THE SCRAPING TOOL, WHEN POSITIONED IN THE RING GROOVE, DOES NOT ENGAGE THE SIDEWALLS OF THE GROOVE EXCEPT ADJACENT THE BASE OF THE GROOVE AND SO THAT WHEN THE TOOL IS MOVED CIRCUMFERENTIALLY WITHIN THE GROOVE IT SCRAPES CARBON ONLY FROM THE BASE THEREOF. 